Usually no. Do not automatically give rifaximin after Zifi CV (cefixime + clavulanate), especially just because diarrhea or stomach upset occurs.

Rifaximin is used for specific conditions such as selected cases of traveler’s diarrhea, IBS with diarrhea, small-intestinal bacterial overgrowth, or hepatic encephalopathy. It is not the standard next antibiotic for routine post-antibiotic diarrhea.

After Zifi CV, first consider antibiotic-associated diarrhea, including possible C. difficile. Adding another antibiotic may worsen the problem. The textbook notes that C. difficile accounts for many cases of antibiotic-related colitis, while mild non-C. difficile diarrhea may be self-limited. - Tintinalli's Emergency Medicine, p. section “When should I follow up with my child's doctor?”

Seek medical review and stool testing promptly if there are:

Avoid self-prescribing rifaximin. The appropriate step depends on why Zifi CV was prescribed, how long it was taken, symptoms, age, pregnancy status, liver disease, and whether C. difficile is suspected. Rifaximin itself can also be associated with C. difficile-associated diarrhea, as its prescribing information warns in the rifaximin safety information.